What you need to know about Zika

No case related to Zika virus reported in India yet, but it is important to be informed

 

After the damaging outbreak of the Ebola virus over the last two years, another little-known infection has prompted the World Health Organisation to declare an international public health emergency. The Zika virus, the first case of which was confirmed last May in Brazil, has since spread rapidly over South and Central America, reaching epidemic proportions.

pread through mosquito bites, the virus is believed to cause brain shrinkage among the newborns of infected pregnant women and in a few cases lead to potentially fatal autoimmune conditions like the Guillain-Barré syndrome.

About 1.5 million Brazilians have caught Zika, while some 3,700 cases of microcephaly, a condition where babies are born with visibly smaller heads and incomplete brain development, are being linked to the virus. While Brazil is worst hit, much of South and Central America have been affected too.

In some regions, a state of emergency has been declared and the army has been called in to battle mosquitoes. The United States reported its first case in February and in times of increased international travel, it is feared the epidemic could soon reach other parts of the world. The threat is compounded by the fact that 80 per cent of those infected do not show any symptom, causing countries to step up efforts to improve testing.

Zika was first isolated in 1947 and outbreaks were limited to Africa, Southeast Asia, and the Pacific Islands. Before 2015, it was largely unknown in the Americas. The virus is transmitted by the aedes aegypti mosquito, which also carries dengue and chikungunya.

It is a day-biting, low-flying mosquito that is commonly found around houses and is known to breed in standing water. Affected persons often show mild symptoms including fever, rash or red eyes, which manifest over a period of five to 14 days after contact with the virus, says Monica Mahajan, senior consultant at Saket’s Max Superspecialty Hospital.

No case has been reported in India yet, but areas experiencing drought or water shortage, where people tend to store water, could be a breeding ground for virus-carrying mosquitoes. Local health organisations have warned pregnant women against travelling to affected countries. The health ministry will also begin screening those who fly back from Latin America. The medical fraternity is awaiting guidelines on which centres would provide diagnostic kits for testing people. 
 

Zika factfile

Symptoms

• Majority of those infected remain asymptomatic or experience mild signs like fever, rash, joint pain or conjunctivitis.
• They could also experience muscle pain and headache. The time between exposure to the Zika virus and visibility of the symptoms is largely considered to be a few days to a week.
• The virus typically remains in the blood of infected persons for a few days but may stay longer in some people.

Treatment

• There is no direct cure yet.
• As with other viral infections, doctors are so far treating the symptoms.
• Hyderabad-based Bharat Biotech claims to have achieved a breakthrough in developing a vaccine. One of the vaccines, it claims, has reached the stage of pre-clinical testing in animals.

Does it kill?

• While the symptoms are usually mild, certain complications like microcephaly or the Guillain-Barré syndrome can prove fatal. Guillain-Barré is a rare disorder in which the body's immune system attacks the nerves. 

How is it different from dengue or chikungunya?

• The three diseases can have overlapping symptoms such as rashes, eye infections, joint and muscle pain. It will require specific tests to determine the presence of Zika virus.

Affected countries

• Much of South America has been hit. While Brazil is worst hit, countries including Puerto Rico, Colombia, Costa Rica, Barbados, American Samoa and Bolivia are facing an epidemic too. Mexico and more recently, the United States have also recorded cases.

Preventive measures for pregnant women

• Pregnant women, who if infected could transmit the virus to their children, have been advised to avoid travelling to affected countries.
• In affected regions, women have been advised to wear long-sleeved clothes and mosquito repellent at all times. 

There is no cure for the virus but a vaccine is expected to be available internationally by August, says Mahesh Lakhe, infectious diseases specialist with Columbia Asia Hospital, Pune. Meanwhile, it is important to build awareness and maintain dry surroundings, adds fellow specialist Om Shrivastav.

“There is a lot of speculation about the virus as research is still ongoing,” says Shrivastav, who has been fielding anxious queries from patients over e-mail and WhatsApp. “The worry is natural since India is prone to dengue outbreaks and could become exposed to spreading of Zika.”